Alien Swarm

Alien Swarm is a freeware multiplayer top-down shooter video game by Valve Corporation. It is a remake of the Alien Swarm mod for Unreal Tournament 2004, and it was developed by the original team, who were hired by Valve Corperation during the course of the development process.

Plot

Campaign: Jacob's Rest

In the game's only official campaign, Jacob's Rest, a swarm of invasive aliens have taken over a colonized planet in December 2052. Marines deployed by the Bloodhound dropship arrive to search for survivors and, if need be, to destroy the colony to prevent the aliens from spreading. The task force kills a large number of not only "normal" Swarm aliens, but alien eggs, large tumor-like growths, parasites and other creatures. They soon find out that the colonists have all been killed by the alien infestation. The marines then guide a thermonuclear bomb (originally meant for excavation purposes) through the complex and activate its timer. They return to the drop ship before the bomb detonates.

Alien Swarm (mod)

Alien Swarm is a total conversion mod for Unreal Tournament 2004 created by Black Cat Games and initially released on May 28, 2004. Alien Swarm, version 1.2 was released on September 10, 2004, with the official campaigns, Sigma and Ortega. Alien Swarm version 1.3, together with a third campaign, Telic, also introducing new weapons and items, plus some bug fixes was released on December 16, 2005. On February 13, 2007 another new campaign and the version 1.32 patch were released. On January 31, 2010 version 1.34 patch was released, adding widescreen support.

In Alien Swarm, the player assumes the role of a commander in the Interstellar Armed Forces and uses the unique skills of the marines at his disposal to fight through infested space ships and colonies that have been overrun by aliens. Alien Swarm can be played both offline and online with up to eight people each controlling one of the eight unique marines. Each marine falls into one of four classes: explosives, special weapons, technical, or medic. The game can be played either as single missions or as a series of missions called a campaign.